How does torque affect car performance?

[CSLACR]

How high you take it in revs all depends on the gearbox as well. At 5000 rpm there is a big torque drop-off already, if you shift a gear up and you end back in the optimal rpm range it's better to shift.

It's not about what you're calling "torque".

Not sure what you mean with torque per minute.

And that's the problem.


At 5,000rpm that graph shows roughly 220hp, which is 1.155 million ft-lb of torque per minute, or 19,257 lb-ft per second.
At 3,000rpm, it is only making 185hp, or roughly 555,000 ft-lb per minute.(9,250 per second)

Which do you think will move you faster, and more quickly? 19,000 lb-ft per second, or 9,000 lb-ft per second?

 

[ghostrider135]

My understanding is torque is the amount of rotational force applied, As opposed to horsepower being linear power from an engine, Hell I even confused myself with that.

I think the most simplistic way I understand it is, Take a prop shaft for example, The more torque you have the easier it is to rotate it and thus get the power (horsepower) where it needs to go.

 

[Scalman2]

As i understand it is cause car to accelerate. So more torque better faster car accelerates when you need it. Hp is not for accelerating. So in game in corners mostly going out from corners you feel that torque. Well you should at least. More torque to wheels more crazy and undriveable car is, even on straight lines.

 

[4everdelayed]

As i understand it is cause car to accelerate. So more torque better faster car accelerates when you need it. Hp is not for accelerating. So in game in corners mostly going out from corners you feel that torque. Well you should at least. More torque to wheels more crazy and undriveable car is, even on straight lines.

HP is a measure of how fast the acceleration will be.

Again, my own car has significantly more torque than F1 engines used a few years. Do you expect a 750hp F1 engine at 18000 rpm to make my car slower than with its stock engine? I don't think so.

It's all about power. When people say that an engine has a lot of torque, they mean that it has a lot of power at low revs. POWER POWER POWER.

 

[Scalman2]

Yes lower revs you have that power better.
And in GTS you could say that bmw m4 gets all that torque too fast so you have no time to react to it if you push it hard from corner.
But tottally different with sls amg. You feel that you have so much power but its somehow more controllable for you to have fun with it.
Car journalists often say: this car has way too much torque its hard to control.
I think its still matter at what range you have that power as torque. More wider range the better

 

[Tekku]

I always see torque as a form of good acceleration.

I once drove a Ford Focus Mk1 TDdi of only 90 BHP company car but it had a really nice flat torque vs rpm curve for a very wide rmp range, meaning regardless of how high or low I was in rpm, if I stepped on the gas then the car was immediately responsive with acceleration (due to having a good amount of torque for that rpm) and it felt really good. It makes the car feel agile at a wide range of rpm for a certain gear you are in.

I have also driven similar TDi cars of 110-115 BHP, that is more power but if the torque vs rpm curve is like a very high and steep "mountain" then the car feels good if you stay in that narrow rpm range, but if you are out of that optimal range then the car feels slow and unresponsive.

Both cars were manual stick shifters and the 90 BHP car was a joy to drive, when I was not in the optimal rpm range to accelerate (for example coming out of a corner or after a traffic manoeuvre), if at any given situation I stepped on the gas pedal I felt immediate reaction and acceleration. Those 110 BPH cars with their less optimal torque curve accelerate faster in their optimal rpm range but once you are a bit below that optimal rpm and hit the gas, it feels very slow in response.

Not sure how all that translates to GT:Sport but that's my real life experience of it.

This for example is a great torque curve, nice flat curve over a wide range of rpm. Basically anything between 1000-6000 will give a fast response in regards of torque. But also looking at the BHP curve, this is an engine that you want to drive in high revs (5000-6500 rpm-ish) for racing since anything lower will have lesser BHP (but still good torque).

And this for example is a worse torque curve, the optimal range only being between 1500-3500 rpm. Add in the BHP as well and this is a car that should be driven to race in the range of 2800-3500 rpm.

Great post. Thanks for sharing!

 

[Scalman2]

Found some interesting stuff


“Below 5252 RPMs any engine’s torque will always be higher than its horsepower, and above 5252 RPMs any engine’s horsepower will always be higher than its torque. At 5252 RPMs the horsepower and torque will be exactly the same.”

And torque to engine not so important as torque to wheels. Thats where gearing comes into game.

 

[VXR]

The easy way to think of it, is why does an S2000 with barely any torque accelerate quicker from a standstill than your average 250 lb ft diesel, but if you tried that from low revs in 4th it would be humiliated. Torque gets the car moving with potential force, power sustains the effort.

 

[Scalman2]

Most low end cars gets so fast from standstill but they loose that fast. Its high gearing lets keep that high torque .then you change gear and its lost as you loose revs.

 

[7HO]

Gears don't multiply torque.

So what you are saying is if I do not have enough torque to move an object then I can't increase my torque with gears to be able to move that object?

If you have not worked it out from that question, you're wrong.

https://www.google.com/search?q=Torque+ratio
https://en.wikipedia.org/wiki/Gear_train#Torque_ratio

 

[Vegard]

So what you are saying is if I do not have enough torque to move an object then I can't increase my torque with gears to be able to move that object?

"Give me a place to stand and with a lever I will move the whole world."

 

[Griffith500]

An engine makes some, varying torque across its entire rev range. That torque is (effectively) a measure of the work done per crank rotation, specifically in the case of ICEs, because of the way their output is measured, and the issues with the asymmetry of the "strokes": e.g. exhaust / induction /compression requires work input before you get more out on the expansion stroke.

Note that work is a thermodynamic term with a specific meaning in this context - it is equivalent to energy. Power is the measure of work done in time, which is why you have to factor in the rotational speed (in time: revolutions per minute). The torque curve is a lovely representation of how well the engine performs at each engine speed, in terms of volumetric and combustion efficiency (less friction) - it is a useful tuning tool, in terms of optimisation. The power curve tells you how fast it can accelerate, which is what really matters.

It is incorrect to suggest that torque matters here and power somewhere else. Both matter everywhere, both do the same thing everywhere. Gearing translates torque to maintain shaft power (less frictional losses etc.) at a different rotational speed: torque multiplication.


Where torque might matter is in the consideration of traction, i.e. thrust force at the contact patch, but gearing can partially neutralise that in a racing context. I.e. a given power figure (acceleration rate) at the wheels represents a fixed thrust force (for the same wheel on the same car at the same speed), no matter the original engine crankshaft torque (the crank power will be the same as that at the wheels, minus losses). It should be clear how gearing affects the available torque / thrust / power for a given corner (speed), although it is complicated by non-constant torque / power output from the engine at different crank speeds.

However, the dynamics of how torque is built (boost threshold, lag, throttle response, torque curve) in relation to control inputs and engine speed can make an engine more or less susceptible to break traction. High rpm often means high inertia, which can help prevent breaking traction, but makes it harder to bring it back once it has broken traction (e.g. Honda 2&4 in GT Sport, its engine has waaaay too much inertia).

 

[Johnnypenso]

It's not about what you're calling "torque".

And that's the problem.


At 5,000rpm that graph shows roughly 220hp, which is 1.155 million ft-lb of torque per minute, or 19,257 lb-ft per second.
At 3,000rpm, it is only making 185hp, or roughly 555,000 ft-lb per minute.(9,250 per second)

Which do you think will move you faster, and more quickly? 19,000 lb-ft per second, or 9,000 lb-ft per second?

Aka "work" or force operating through distance or time. One might say torque in motion rather than a snapshot. A very important concept in this context:tup:.

 

[Skygrasper550]

Torque is the tendency of the wheels to rotate, while horspower is the maximum rotation speed of the wheels.

Example of high torque/low hp: wheel generates only 35hp but gets up to 35hp in just 2 seconds.

Example of low torque/high hp: wheel reaches up to 80hp, but requires about 10 seconds to reach that 80hp.

You'll understand this better if you drive the Porsche 911 GT3 RS and Mercedes AMG GT-S around the same track, using Racing tires. Since the AMG has a lot more torque, its drive wheels tend to rotate faster, and so you tend to break the traction of the rear tires more often in low-speed corners.

 

[Zenmervolt]

Gears don't multiply torque. (except on machines calibrated for a 1-1 gearing ratio)
Your vehicle makes effectively the same power and "torque"(which horsepower is) in every gear.

Well this is just wrong.

Gearing multiplies torque. Torque is *not* horsepower.

Horsepower is the product of torque and RPM divided by 5252. If gears changed RPM without also changing torque, they would change horsepower too. But they don't change horsepower.

A gearset that cuts RPM in half doubles torque (ignoring frictional losses). Because the RPM is halved, the horsepower remains constant even though the torque at the output is double the torque at the input for the gearset.

The reason shorter gears allow a car to accelerate more quickly is that they provide more torque multiplication. That extra torque multiplication is why the car, as you say, "reaches peak power more quickly." It gets there more quickly because there is more torque at the wheels, as a result of lower gearing.

As for when to shift, for optimal acceleration, you shift at the earlier of:
(1) the RPM at which torque at the wheels in the current gear has just become lower than what the torque at the wheels would be after the shift, or
(2) maximum engine RPM.

As a practical matter, this usually ends up being redline unless the engine suffers some rather horrific power drop off at high RPM (as many old pushrod V8 engines did before the mid/late 1980s).

 

[CSLACR]

So what you are saying is if I do not have enough torque to move an object then I can't increase my torque with gears to be able to move that object?

If you have not worked it out from that question, you're wrong.

https://www.google.com/search?q=Torque+ratio
https://en.wikipedia.org/wiki/Gear_train#Torque_ratio

You can increase the torque applied, at a given speed.
I detailed this for you already.
But I'll do it a bunch of times in every post so it gets ignored even more.

A gear optimized for torque(horsepower) at 30mph, has more torque at 30mph. What about 40mph? Will a gear optimized for maximum torque applied at 30mph apply even more torque at 40mph? Nope, but a longer gear (that, as you claim) doesn't "multiply torque as much") that is optimized for 40mph will give you more torque at 40mph.
"Without multiplying torque more???" Gears don't multiply torque.

Gears multiply torque applied at a given speed, on the concept that what is attached to them(engine) has more power at a faster speed.

Torque is the tendency of the wheels to rotate, while horspower is the maximum rotation speed of the wheels.

Oh my god, you haven't read anything and couldn't be much more wrong.

Well this is just wrong.

Gearing multiplies torque. Torque is *not* horsepower.

Horsepower is the product of torque and RPM divided by 5252. If gears changed RPM without also changing torque, they would change horsepower too. But they don't change horsepower.

A gearset that cuts RPM in half doubles torque* (ignoring frictional losses). Because the RPM is halved, the horsepower remains constant even though the torque at the output is double the torque at the input for the gearset.

The reason shorter gears allow a car to accelerate more quickly is that they provide more torque multiplication. That extra torque multiplication is why the car, as you say, "reaches peak power more quickly." It gets there more quickly because there is more torque at the wheels, as a result of lower gearing.

As for when to shift, for optimal acceleration, you shift at the earlier of:
(1) the RPM at which torque at the wheels in the current gear has just become lower than what the torque at the wheels would be after the shift, or
(2) maximum engine RPM.

As a practical matter, this usually ends up being redline unless the engine suffers some rather horrific power drop off at high RPM (as many old pushrod V8 engines did before the mid/late 1980s).

Multiplied.
*Applied torque at a given speed. A gear that "multiplies" torque optimally for 30mph, won't be applying as much torque at 40mph as a longer gear optimized for 40mph.
You're also completely ignoring the fact the engine might make significantly more or less than half the power at half the rpm.
You also seem to be ignoring that horsepower and torque, are both torque.
But obviously you either didn't read or understand my post.

 

[Griffith500]

Aka "work" or force operating through distance or time. One might say torque in motion rather than a snapshot. A very important concept in this context:tup:.

Yes, sort of - work is force-distance and work per time is power, i.e. energy per time.
Force itself per time doesn't have much of a useful interpretation, nor torque per time.

With torque, the distance that the force acts through (to do work) is the perimeter of the circle or arc of the lever arm.

Torque is the tendency of the wheels to rotate, while horspower is the maximum rotation speed of the wheels.

Example of high torque/low hp: wheel generates only 35hp but gets up to 35hp in just 2 seconds.

Example of low torque/high hp: wheel reaches up to 80hp, but requires about 10 seconds to reach that 80hp.

You'll understand this better if you drive the Porsche 911 GT3 RS and Mercedes AMG GT-S around the same track, using Racing tires. Since the AMG has a lot more torque, its drive wheels tend to rotate faster, and so you tend to break the traction of the rear tires more often in low-speed corners.

It's the (net) power that dictates how long it takes to accelerate the wheels, according to their mass moment of inertia. In order for there to be a thrust at the tyre, the wheel needs to be accelerated first, of course. If there is a lot of torque at low rpm, there is a lot of power there too, that means there is more power to accelerate the wheels more quickly.

Instead, compared with a "low torque" engine, a "high torque" engine requires fewer rotations itself to impart a given amount of energy to the wheels, i.e by accelerating them from one speed to another. That doesn't really say much about how fast everything else is spinning or how long it takes. Engines are quite finicky about which speeds they make useful torque, and power, by extension.

 

[Zenmervolt]

A gear that "multiplies" torque optimally for 30mph, won't be applying as much torque at 40mph as a longer gear optimized for 40mph.

Nope, you're still very, very wrong. Or, in the alternative, explaining your position very, very poorly.

Assuming identical input torque, a gear that provides more torque at 30 mph will still provide more torque at 40 mph.

Gears multiply torque. That's what they do, that's how they work. It's very basic physics.

Now, as an overall system, it's possible that a particular engine with your "30 mph" gearset will either be unable to rev high enough to reach 40 mph in the same gear or will have such a massive fall off in torque at the necessary input RPM that the "30 mph" gear results in less net torque at the wheels than a taller "40 mph" gear despite the fact that the "40 mph" gear is actually providing less multiplication, but that doesn't change the underlying fact that the gears are unquestionably still multiplying input torque.

You say that "horsepower and torque, are both torque." But this is not true. Horsepower is derived from a combination of torque and RPM. You need both torque and RPM to have horsepower. To say that horsepower "is" torque is to oversimplify things to the point of being wrong.

 

[Ian Fairbanks]

Horsepower is how fast you hit the wall.

Torque is far you move there wall after you hit it.

Came here to say this. Torque does play a role in when you shift. For instance, the diesel powered Mazda atenza can be short shifted for better acceleration, it’s got no torque on top end.

To quote Mr. Ferrari “horsepower sells cars, torque wins races.”

 

[4everdelayed]

This thread jesus christ

Some people need to forget about torque. Pretend it never existed. Dont ever use that word again. Delete it from your vocabulary.

 

[SleezyBigSlim]

High torque means good acceloration, makes it easy to pass cars on the highway or speed up quickly at high speeds and RPM

 

[Scaff]

High torque means good acceloration, makes it easy to pass cars on the highway or speed up quickly at high speeds and RPM

Not without the right gearing it doesn't.

I'm fairly certain that every big-rig has significantly more torque than my V40 D4, yet I know who would win in a drag race.

Gears don't multiply torque. (except on machines calibrated for a 1-1 gearing ratio)

Yes they do.

Your vehicle makes effectively the same power and "torque"(which horsepower is) in every gear.

Nope. Torque and power are related by they are most certainly not the same thing at all.

The base values will be the same at the engine for any given gear, but they will not be the same at the wheels, as gears are force multipliers but not power multipliers. Its basic physics. Its why crowbars, wreaking bars, levers, pulleys and gears work.

If they were not force multipliers the entire industrial age would not have happened!

Gearing changes your rpm at a given speed, in a given gear. A car that has 500hp at 5,000rpm, has 500hp in 1st gear, and also has 500hp in 4th. Outside of some very small potential frictional/weight differences, of course.

It does indeed, but bhp isn't torque.

Cars accelerate faster with quick gears, because they reach peak power more quickly.
If you drag race two cars, with different gear sets, you can usually make a movie out of it, because the quick gearing car pulls ahead, then shifts as the longer geared car hits peak power, and takes it's turn pulling ahead. No, it doesn't work that easily in every scenario, but it does in many.

Nope. You can potentially accelerate faster with different gears because they increase the work the wheel is doing by multiplying the torque from the engine to the driven wheels.

Just for example, a car might reach 130mph in 4th gear @ 6,000rpm(max). 5th gear is too long to accelerate with, 130mph top speed.
Shorten the gearing so 4th reaches 120mph @6000rpm, and it will accelerate to the end of 4th gear more quickly, but won't reach 130mph as quickly, if at all. Shorten it even more, 4th only reaches 110mph, now the car can pick up speed in 5th gear. Now the car accelerates faster constantly, and reaches 130mph quicker than the original, but also has a top speed of 137mph.
On the opposite end of the spectrum, lengthen the gears. Now 4th gear reaches 137mph, but the acceleration is slowed.

BHP's still not torque.

Why? The amount of time spent at maximum horsepower.

Which has nothing to do with torque.

Ya know what never, ever happens? Changing a gear ratio and suddenly having 510hp on your 500hp car.

No one has said it does, because BHP still isn't torque.

If anyone disagrees, feel free to link the horsepower-adding gear set for sale.

Strawman based on your own inability to understand that BHP isn't torque.

Its really quite simple.

BHP is a measure of power, Torque is a measure of force (ratational force in this case) and gearboxes are a torque multiplier.

https://en.wikipedia.org/wiki/Horsepower
https://en.wikipedia.org/wiki/Torque
https://en.wikipedia.org/wiki/Torque_multiplier
https://en.wikipedia.org/wiki/Gear_train#Torque_ratio

https://www.google.co.uk/search?q=e...69i59j69i57.5876j0j7&sourceid=chrome&ie=UTF-8

 

[Ian Fairbanks]

Kids! Kids! Kids... c’mon.... don’t banter. Instead, test it on course. This is a video game. And although PD did their best to make it “real” that doesn’t even mean that real life philosophy applies. Go test your theories on track. Come back with proof. Moving on...

 

[Scaff]

Kids! Kids! Kids... c’mon.... don’t banter. Instead, test it on course. This is a video game. And although PD did their best to make it “real” that doesn’t even mean that real life philosophy applies. Go test your theories on track. Come back with proof. Moving on...

I'm 47.

 

[Ian Fairbanks]

I'm 47.

And I’m 33. Yet we all go back forth like chitlins. I’m just trying to cool the bricks here man. The thread is derailing.

 

[Scaff]

And I’m 33. Yet we all go back forth like chitlins. I’m just trying to cool the bricks here man. The thread is derailing.

If you believe that to be the case then please report it and if needed the staff will take action.

 

[CSLACR]

It does indeed, but bhp isn't torque.

Let's make it simpler.
Show me an engine, with torque ratings, change the gearing, and show me the new higher torque readings.

I already know it doesn't exist.

Also, torque is defined as a rotational force. Horsepower is torque per minute. Rotational force per minute. But it's rotational force that isn't torque? Ok.

 

[Scaff]

Let's make it simpler.
Show me an engine, with torque ratings, change the gearing, and show me the new higher torque readings.

I've already provided a myriad of sources that show that when you transfer force through different gear ratios it changes the output torque in comparison to the input torque.

Are all of these (including the ones from peer reviewed scientific papers) all wrong?

And once again I am not talking about engine torque (and have said that remains unchanged), but output torque at the wheels.

I already know it doesn't exist.

OK.

Also, torque is defined as a rotational force. Horsepower is torque per minute. Rotational force per minute. But it's rotational force that isn't torque? Ok.

Nope, horsepower is the rate at which the work is done. Its not the work itself.

Torque is the work being done, horsepower is the rate at which its done. Levers, pully's and gears can't affect how quickly it gets done (the power) but they do affect the force itself.

That's why torque and horsepower are related, but they are not, not have they ever been the same thing.

You as an individual have a limit to the amount of power you are able to generate, however the amount of force you are able to apply will vary depending on how you use it.

If you can apply 50lbs of force with a 1 foot lever (50 ftlbs), you can with a 2 foot lever apply 100lbs of force (100 ftlbs), increase that level to ten foot and you can now apply 500lbs of force (500ftlbs).

http://www.explainthatstuff.com/gears.html

 

[CSLACR]

I've already provided a myriad of sources that show that when you transfer force through different gear ratios it changes the output torque in comparison to the input torque.

Are all of these (including the ones from peer reviewed scientific papers) all wrong?

And once again I am not talking about engine torque (and have said that remains unchanged), but output torque at the wheels.


OK.




Nope, horsepower is the rate at which the work is done. Its not the work itself.

Torque is the work being done, horsepower is the rate at which its done. Levers, pully's and gears can't affect how quickly it gets done (the power) but they do affect the force itself.

That's why torque and horsepower are related, but they are not, not have they ever been the same thing.

You as an individual have a limit to the amount of power you are able to generate, however the amount of force you are able to apply will vary depending on how you use it.

If you can apply 50lbs of force with a 1 foot lever (50 ftlbs), you can with a 2 foot lever apply 100lbs of force (100 ftlbs), increase that level to ten foot and you can now apply 500lbs of force (500ftlbs).

http://www.explainthatstuff.com/gears.html

Ok, so gears multiply torque.

Logic time
1. Gears multiply torque
2. Put gears on that "double your torque"
3. Make 400hp car race with 800hp car because it's torque has been doubled!

Outside of foolish semantics, like assuming the 800hp engine has horrific gearing, it just won't work.
You can post as many graphs and links as you want, but it doesn't work that way.

Because like I said, gears multiply torque applied at a given speed.
The entire point you're trying to make is based on comparing a car stuck in a 1-1 ratio vs a car with gearing, and also completely ignoring the axle ratio while you're at it.
If my axle is 2-1, and my gear is 2-1, I'm at a 4-1 ratio.
If your axle is 1-1, and your gearing is 3-1, you're at 3-1.
But wait, your gears are "multiplying" torque more than mine, right? And yet I have the quicker ratio, and quicker acceleration, because my rpm's will be higher at a given speed. My "torque is multiplied" more than yours.

P.S. Gears and levers aren't the same, you'd do well to stop speaking of them as twins.

 

[Scaff]

Ok, so gears multiply torque.

Logic time
1. Gears multiply torque
2. Put gears on that "double your torque"
3. Make 400hp car race with 800hp car because it's torque has been doubled!

No, no, no, no.

Gears multiple output torque.

The torque at the engine is unchanged, so the hp is unchanged. The gears multiple the torque at the driven wheels, The engine torque (and therefore hp) is utterly unchanged.

Outside of foolish semantics, like assuming the 800hp engine has horrific gearing, it just won't work.
You can post as many graphs and links as you want, but it doesn't work that way.

Becuase you are assuming taht somehow gears increase the engine torque rather than the torque at the driven wheels.

Because like I said, gears multiply torque applied at a given speed.
The entire point you're trying to make is based on comparing a car stuck in a 1-1 ratio vs a car with gearing, and also completely ignoring the axle ratio while you're at it.
If my axle is 2-1, and my gear is 2-1, I'm at a 4-1 ratio.
If your axle is 1-1, and your gearing is 3-1, you're at 3-1.
But wait, your gears are "multiplying" torque more than mine, right? And yet I have the quicker ratio, and quicker acceleration, because my rpm's will be higher at a given speed. My "torque is multiplied" more than yours.

Its not ignoring the axle ratio at all, that's still gearing.

P.S. Gears and levers aren't the same, you'd do well to stop speaking of them as twins.

Both are force multipliers, as such in that regard yes they are.

It does however show that you clearly didn't bother following any of the provided links.